Coal concentration



Aug. 10-, 1926. 1,595,745

- W. TRURAN COAL CONCENTRATION Filed May 24. 1922 INVENTOR Patented Aug. 10, 1926. v

UNITED STA ES PATENT orsics.

WILLIAM TRUBAN, F YOLANDA, QALIFOBNIA, ASSIGNOR TO MINERALS SEPARATTON NORTH AMERICAN CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF MARYLAND.

COAL ooncnn'rna'rron.

Application filed llay 24, 1922. Serial natasn.

. world a relatively cheap material, the cost of the reagents used in effecting froth-flotatlOIl concentration-of the coal becomes an important item where such concentration .is-

Item the spltzkasten nto the agitation necessary or is advisable for any purpose.

According to th present invention, instead of adding a frothing agent to the pulp of ground coal and water at the'beginning'of the operation, the concentration is commenced by agitating and aerating the coal pulp in the usual manner for frothfiotation concentration, without the addition of an agent, so that a substantial portion of the coal is raised in a coal-bearing froth. An agent is then added to the depleted pulp and the concentration ofthe coal completed by further agitation and aeration to produce further coal-bearing froth. The coal-bearing froths are separated from the pulps in the usual manner and the entire operation may be continuous. It is found that by working in this manner, the amount of added agent used to effect the complete concentration of the coal is substantially reduced with resulting economy.

' The examples herein described were carried out in a subaeration machine of the kind shown in sectional side view in the accompanying drawing.

This machine has an agitation chamber 1, of rectangular cross-section, provided with an agitator 2 turning near the bottom of the chamber and carried by a s 1aft 3, which is journaled in overhead bearings 4 and 5, and has a driving ulley 6, at the top, and is supported just below the pulley by a suitable thrust bearing 7 v To form a froth, the agitator 2 is in-the proper direction at a suitable speed and air is thereby drawn in through a bottom pipe 9, suitably connected by a U-extension to an upright pipe 10, extending above the level of the pulley in the chamber 1 and provided with a valve 11 to control the admission of air beneath the agitator 2. A suitable baflle 12 is located above the agitator 2, and is shown as formed of intersecting same Eastern driven metal sheets 13 and 14., set at right angles to each other. f

Alongside of the agitation chamber 1 is formed a spitzkasten -18 and the wall 17 between the agitation chamber and the spitzkasten terminates at the top below the I pulp level, and provides communication at the bottom between the agitation chamber and spitzkasten, thus permitting the pulp to flow over the top of this partition into the spitzkasten and to flow downward and back 6 Company, suitably ground to pass a tenmesh Tyler screen, was made into a pulp-7 with water and agitated and aerated for five minutes without the addition of any agent and a coal-bearing froth formed. There was then added 0.3 pounds per ton of commercial cresylic acid and 0.6 pounds per ton of Eastern fuel oil. Agitation was continued for another five minutes, and fur: ther coal-bearing froth was formed.- The" overflow of froth was continuous from the first formation thereof to the end of the total ten-minute period of'agitatiop. The concentrate thus obtained was further treated by reagitation for ten minutes in the same machine to produce a cleaner froth with addition of 0.1 pound per ton of the same cresylic acid, 0.5 pounds per ton of the fuel oil, and 0A pounds per ton of starch, the latter being added infthe form of a thin paste. The results are shown .in the following table v rms. %Recovl Wt. Ash. S. good ery good 1 coal. coal.

Heads iooo .11.; 219 355.0 Conc... sac 6.8 0.99 353.4 99.6 Tailings 11.4 as. o 11. 5 1.6

2. grams of coal from the Freeport seam of the American Manganese Manufacsame cresyl'ic acid and chine without the addition of any agent, forming a coal-bearing froth. There was then added 0.4 pounds er ton each of the astern fuel oil and agitation was continued for three minutes, forming further coal-bearing froth. The total overflowing froth was collected. results are shown in the following table Grms. %Recov- Wt. Ash. S. good ery good coal. coal.

Heads 100. 0 14. 3 1. 43 290 Conc 86. 6 7. 2 l. 09 288 99. 3 Tailings 13. 4 60. 6 2. 91 2 3. 500 grams of coal from the American Manganese Manufacturing Company was ground to pass through a ten-mesh standard Tyler screen, and was agitated for three minutes without the addition of any agent and a coal-bearing froth formed. There was then added 1.3 pounds per ton of Eastern fuel oil.

Agitation was continued for another five minutes, and further coal-bearing froth was formed. The overflow of froth was continuous from the first formation thereof to the end of the total ten-minute period of agitation. The results are shown in the following table Grms. Recov- Wt. Ash. S. good ery good coal. coal.

Heads 100. o 13. 9 65. 1 525. 5 C0uc 77.9 7. 4 79.0 307.9 94. 3 Tails 22. l 36. 6 15. 9 l7. 6 Q.

' bearing material which consists in agitating and aerating a pulp of the suitably ground materlal to produce ,a coal-bearing froth without addition of an agent, then adding an agent to the depleted pulp and subject The ing the depleted pulp to further agitation and aeration to form further coal-bearing froth, and separating the froths from the pulps. r.

2. The process of concentrating coalbearing material which consists in agitating and aerating a pulp of the suitably ground material to produce a coal-bearing froth without addition of an agent, then adding an oily agent to the depleted pulp and subjecting the depleted pulp to further agitation and aeration to form further coal-bear ing froth, and separating the froths from the pulps.

3. The process of 'concentrating'coalbearing material which consists in agitating and aerating a pulp of the suitably ground material to produce a coal-bearing froth without addition of an agent, then adding an oil and a soluble frothing agent to the depleted pulp and subjecting the depleted pulp to further agitation and aeration to form further coal-bearing froth, and separating the froths from the pulps.

4. The process of concentrating coalbearing material which consists in agitating and aerating a pulp of the suitably ground material to produce a coal-bearing froth without addition of an agent, then adding a petroleum oil and a soluble frothing agent to the depleted pulp and subjecting the de-' ple ted pulp to furtheragitation and aerationto form'further coal-bearing froth, and

. separating the froths from th pulps.

5. The process ofv concentrating coalbearing. material which consists in agitating and aerating a pulp of the suitably ground material to produce a coal-bearing froth Without addition of an agent, se arating the froth from the pulp, thenad ing anv oily agent to the depleted pulp and subjecting the depleted pulp to further agitation and aeration to form further coal-bearing froth and separating this froth from the pulp, {thenreagitating and reaerating the commingled froths with the addition of a small quanti-tyof starc to' form a cleaner froth, and separati g the cleaner froth.

In testimony, whereof, Ihave affixed my signature to this specification.

WILLIAM TRURAN. 

